fontdialog.java

Java Classic Examples是我买的两本书：《JAVA经典实例》和《java入门经典源代码》里边附送光盘里带的源码

// Class to define a dialog to choose a font
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import java.awt.event.*;

class FontDialog extends JDialog
                 implements Constants,
                            ActionListener,         // For buttons etc
                            ListSelectionListener   // For list box
{
  // Constructor
  public FontDialog(SketchFrame window)
  {
    // Call the base constructor to create a modal dialog
    super(window, "Font Selection", true);   

    this.window = window;                          // Save the window reference
    font = window.getCurrentFont();                // Get the current font
    fontStyle = font.getStyle();                   // ...style
    fontSize = font.getSize();                     // ...and size

    // Create the dialog button panel 
    JPanel buttonPane = new JPanel();             // Create the panel to hold buttons

    // Create and add the buttons to the buttonPane
    buttonPane.add(ok = createButton("OK"));              // Add the OK button
    buttonPane.add(cancel = createButton("Cancel"));      // Add the Cancel button
    getContentPane().add(buttonPane, BorderLayout.SOUTH); // Add pane to content pane

    // Code to create the data input panel
    JPanel dataPane = new JPanel();                    // Create the data entry panel
    dataPane.setBorder(BorderFactory.createCompoundBorder(   // Create pane border
                       BorderFactory.createLineBorder(Color.black),
                       BorderFactory.createEmptyBorder(5, 5, 5, 5)));  
    GridBagLayout gbLayout = new GridBagLayout();            // Create the layout
    dataPane.setLayout(gbLayout);                            // Set the pane layout
    GridBagConstraints constraints = new GridBagConstraints();

    // Code to create the font choice and add it to the input panel
    JLabel label = new JLabel("Choose a Font");
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.gridwidth = GridBagConstraints.REMAINDER; 
    gbLayout.setConstraints(label, constraints);
    dataPane.add(label);

    // Code to set up font list choice component
    GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
    String[] fontNames = e.getAvailableFontFamilyNames();  // Get the font names

    fontList = new JList(fontNames);                     // Create list of font names
    fontList.setValueIsAdjusting(true);                  // single event selection
    fontList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); // Choose 1 font
    fontList.setSelectedValue(font.getFamily(),true);
    fontList.addListSelectionListener(this);
    JScrollPane chooseFont = new JScrollPane(fontList);  // Scrollable list
    chooseFont.setMinimumSize(new Dimension(300,100));

    // Panel to display font sample
    JPanel display = new JPanel();
    fontDisplay = new JLabel("Sample Size: x X y Y z Z");
    fontDisplay.setPreferredSize(new Dimension(300,100));
    display.add(fontDisplay);

    //Create a split pane with font choice at the top
    // and font display at the bottom
    JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,
                                          true,
                                          chooseFont,
                                          display);
    gbLayout.setConstraints(splitPane, constraints);   // Split pane constraints
    dataPane.add(splitPane);                           // Add to the data pane

    // Set up the size choice using a combobox
    JPanel sizePane = new JPanel();                 // Pane for size choices
    label = new JLabel("Choose point size");        // Prompt for point size
    sizePane.add(label);                            // Add the prompt
    String[] sizeList = { "8", "10", "12", "14", "16",        // Array of sizes
                          "18", "20", "22", "24"};
    chooseSize = new JComboBox(sizeList);                     // Size choice combobox
    chooseSize.setSelectedItem(Integer.toString(fontSize));   // Default selection
    chooseSize.addActionListener(this);                       // Add size listener
    sizePane.add(chooseSize);                                 // Add combobox to pane
    gbLayout.setConstraints(sizePane, constraints);           // Set pane constraints
    dataPane.add(sizePane);                                   // Add the pane
  
    // Set up style options using radio buttons
    JRadioButton bold = new JRadioButton("Bold", (fontStyle & Font.BOLD) > 0);
    JRadioButton italic = new JRadioButton("Italic", (fontStyle & Font.ITALIC) > 0);
    bold.addItemListener(new StyleListener(Font.BOLD));       // Add button listeners
    italic.addItemListener(new StyleListener(Font.ITALIC));
    JPanel stylePane = new JPanel();                          // Create style pane
    stylePane.add(bold);                                      // Add buttons
    stylePane.add(italic);                                    // to style pane...
    gbLayout.setConstraints(stylePane, constraints);          // Set pane constraints
    dataPane.add(stylePane);                                  // Add the pane

    getContentPane().add(dataPane, BorderLayout.CENTER);
    pack();
    setVisible(false);
  }

  JButton createButton(String label)
  {
    JButton button = new JButton(label);                  // Create the button
    button.setPreferredSize(new Dimension(80,20));        // Set the size
    button.addActionListener(this);                       // Listener is the dialog
    return button;                                        // Return the button
  }

  public void actionPerformed(ActionEvent e)
  {
    Object source = e.getSource();                // Get the source of the event
    if(source == ok)                              // Is it the OK button?
    {
      window.setCurrentFont(font);                // Set the selected font
      setVisible(false);                          // Hide the dialog
    }
    else if(source == cancel)                     // If it is the Cancel button
      setVisible(false);                          // just hide the dialog
    else if(source == chooseSize)
    {
      fontSize = Integer.parseInt((String)chooseSize.getSelectedItem());
      font = font.deriveFont((float)fontSize);
      fontDisplay.setFont(font);
      fontDisplay.repaint();
    }
  }

  // List selection listener method
  public void valueChanged(ListSelectionEvent e)
  {
    if(!e.getValueIsAdjusting())
    {
      font = new Font((String)fontList.getSelectedValue(), fontStyle, fontSize);
      fontDisplay.setFont(font);
      fontDisplay.repaint();
    }
  }

  class StyleListener implements ItemListener
  {
    public StyleListener(int style)
    {  
      this.style = style;  
    }

    public void itemStateChanged(ItemEvent e)
    {
      if(e.getStateChange()==ItemEvent.SELECTED)   // If style was selected
        fontStyle |= style;                        // turn it on in the font style
      else
        fontStyle &= ~style;                       // otherwise turn it off

      font = font.deriveFont(fontStyle);           // Get a new font
      fontDisplay.setFont(font);                   // Change the label font
      fontDisplay.repaint();                       // repaint
    }    
 
    private int style;                             // Style for this listener
  }

  private SketchFrame window;        // The application window
  private Font font;                 // Currently selected font
  private int fontStyle;             // Font style - Plain,Bold,Italic
  private int fontSize;              // Font point size
  private JButton ok;                // OK button
  private JButton cancel;            // Cancel button
  private JList fontList;            // Font list
  private JComboBox chooseSize;                     // Font size options
  private JLabel fontDisplay;                       // Font sample
}